A serologic study of canine herpes virus-1 infection in the Norwegian adult dog population

Canine herpes virus-1 (CHV1) causes a fatal hemorrhagic disease in neonatal puppies and is associated with reproductive problems in female dogs. This serologic study was conducted to assess the seroprevalence of CHV1 infection in Norway. Blood samples were collected from clinically healthy dogs (n = 436) one yr of age and older of both genders, supplied by four small animal clinics (A, B, C and D) in different parts of the country. The immunoperoxidase monolayer assay was used for testing of CHV1 antibodies. Serum titers were recorded as the reciprocal value of the highest dilution producing specific cell staining. Titers equal to or above 80 were considered positive for exposure to CHV1. In total, 80.0% of the dogs had titers ≥80 and were classified as positive. Mean age for seronegative dogs was 4.7 yrs (95% CI 4.1-5.4) and for seropositive dogs 5.0 yrs (95% CI 4.7-5.4). Of the dogs, 32.8% displayed a weakly positive titer of 80, whereas 41.5 and 5.7% fell into the moderately (titer 160 and 320) and strongly (titer ≥640) positive categories, respectively. No association was demonstrated when comparing CHV1 antibody titers to gender or reproductive parameters like previous matings, pregnancies, births or number of puppies born. Age, visit in foreign countries and clinic explained together 78% of the variation in antibody titer categories. The percentage of positive samples differed significantly between the four clinics (A 98%, B 58.5%, C 74.6%, D 89.5%). A reasonable explanation for this finding has not been established. No information about an ongoing outbreak of CHV1 infection was available. In conclusion, this study strongly indicates that CHV1 infection is endemic in the dog population of Norway. There are significant differences in seroprevalence between geographic regions in the country.     

A glycol methacrylate method for the routine histologic evaluation of rat inner ear

A method has been developed for the histologic evaluation of rat inner ear using glycol methacrylate (GMA) and steel knife sectioning. The necropsy, fixation, and histologic techniques described are not so complex and difficult as to preclude their routine use. The method is particularly useful in studies in which the entire inner ear of a large number of animals must be evaluated histologically.     

Effects of hypo- and hyper-capnia on myocardial blood flow and metabolism during epinephrine infusion in the dog

We have previously demonstrated a 40% increase in myocardial blood flow (MBF) during hypercapnia but no significant decrease of MBF during hypocapnia. The present study was undertaken to evaluate if epinephrine infusion, which increases both myocardial oxygen consumption (MVo2) and myocardial performance, might influence the effects of hypocapnia and hypercapnia on MBF. Induction of hypocapnia was performed by hyperventilation in closed-chest dogs anesthetized with pentobarbital. By adding carbon dioxide to the inspiratory gas, normocapnia and hypercapnia were created. Epinephrine infusion (0.8 microgram X kg-1 X min-1) increased MBF and cardiac output (CO) by 90 and 140%, respectively, while MVo2 was increased by 45%. Epinephrine had a direct coronary vasodilating effect in excess of myocardial needs evidenced by increased oxygen content of the coronary sinus blood. During epinephrine infusion, induction of hypocapnia effected no change of MBF, while myocardial oxygen extraction increased significantly. Although oxygen saturation (So2) and Po2 in the coronary sinus blood decreased, these values remained well above those with hypocapnia without epinephrine infusion, thereby excluding impaired oxygen supply to the heart. Hypercapnia induced an increase of MBF by nearly 40% despite the coronary vasodilatation already induced by epinephrine infusion.     

The Blood Bank as a Public Health Service

The donation of blood is presented to the public as an altruistic service in which one human helps another. At the same time, the donor receives some help for himself. In the process of blood donation, a medical history is taken, an extremely short physical examination is done, and the donor''s blood is studied by various tests. Although this is by no means the equivalent of a complete physical examination performed by a physician, it sometimes can be helpful in discovering early disease or other medical findings which could be pertinent to the donor''s health.     

Effects of Leaf Shape and Boundary Layer Thickness on Photosynthesis in Cotton (Gossypium hirsutum)

In upland cotton (Gossypium hirsutum L.) certain varieties are available with the mutant character “okra” leaves. These deeply lobed leaves were found to have thinner boundary layers than their normal analogues. Apparent photosynthesis and transpiration measurements were made in field-grown stands under a variety of light intensities and carbon dioxide levels to assess the effect of leaf boundary layer diffusion resistance on photosynthetic efficiency. The thinner boundary layers associated with deeply lobed “okra” cotton failed to euhance carbon fixation rates per unit land area. It was concluded that the leaf boundary layer resistance under field conditions is small compared with the total CO₂ diffusion resistance.     

Preparation and Test In G Of Silver-Protein Compounds

Silver derivatives of the protargol type were made from 13 different commercial peptones. The peptone samples were purified by precipitating with an ethanol concentration of 75%, reprecipitating once, and discarding any water-insoluble material. A 20-22% solution of the purified material in water, allcalinized with 2 ml. of strong ammonia per 100 ml., was precipitated by adding an equal volume of 25% aqueous AgNO₃, and stood in a refrigerator overnight. Thorough washing of the precipitate with distilled water, draining, and then dissolving it in a purified peptone solution (30-35% aqueous), whose volume was 0.6 that of the solution used for silver precipitation, gave the soluble silver derivative. Ammonia was added to facilitate solution and the final pH adjusted to 8.0-8.4. The concentrated solution was dehydrated either with acetone or in a dessicator under reduced pressure and ground to a powder. Staining tests on neurological tissue showed that the Pharmaceutical peptone (Cudahy Packing Co., Omaha, Nebr.) and the Bacteriologic peptone (Wilson Laboratories, Chicago, 111.) gave the best preparations for staining nerve fibers, and that these were essentially equal to the formerly available German made Protargol.     

Importance of polyamines in cell cycle kinetics as studied in a transgenic system

Polyamines are organic cations, which are considered essential for normal cell cycle progression. This view is based on results from numerous studies using a variety of enzyme inhibitors or polyamine analogues interfering with either the metabolism or the physiological functions of the polyamines. However, the presence of non-specific effects may be hard to rule out in such studies. In the present study, we have for the first time used a transgenic cell system to analyze the importance of polyamines in cell growth. We have earlier shown that expression of trypanosomal ODC in an ODC-deficient variant of CHO cells (C55.7) supported growth of these otherwise polyamine auxotrophic cells. However, one of the transgenic cell lines grew much slower than the others. As shown in the present study, the level of ODC activity was much lower in these cells, and that was reflected in a reduction of cellular polyamine levels. Analysis of cell cycle kinetics revealed that reduction of growth was correlated to prolongation of the G₁, S, and G₂ + M phases in the cells. Providing exogenous putrescine to the cells resulted in a normalization of polyamine levels as well as cell cycle kinetics indicating a causal relationship.     

Metalloprotease disintegrin-mediated ectodomain shedding of EGFR ligands promotes intestinal epithelial restitution

EGF receptor (EGFR) promotes intestinal epithelial restitution, an important early process in the reepithelialization of ulcers. During epithelial restitution, the mechanism of EGFR activation is not known. We evaluated the role of TNF-converting enzyme (TACE), a metalloprotease disintegrin that proteolytically processes plasma membrane-anchored EGFR ligand precursors into their mature active forms, in wound-induced EGFR activation and epithelial restitution. With the use of scrape-wounded rat intestinal epithelial-1 (RIE-1) cell monolayers to model epithelial ulceration and restitution, we observed the rapid wound-dependent release of EGFR ligands into culture medium. RIE-1 cells express TACE, and treatment with phorbol ester, an established TACE stimulus, triggered the extracellular release of an EGFR ligand, transforming growth factor-alpha. Blockade of TACE using TNF processing inhibitor (TAPI-1), a specific hydroxamate inhibitor of metalloprotease disintegrins, prevented release of EGFR ligands from wounded RIE-1 cell monolayers. The restitution of wounded RIE-1 cell monolayers was also dose-dependently inhibited by TAPI-1, establishing the role of metalloprotease disintegrins in this process. These results have established a mechanism of EGFR activation in wounded intestinal epithelium and show an important functional role for metalloprotease disintegrin-mediated ectodomain shedding during intestinal epithelial restitution. Therefore, activation of the TACE-EGFR system might promote the healing of intestinal tract ulcers in patients.